1. Field of the Invention
The present invention relates to an improved apparatus for regenerating desiccant in a closed cycle and, more particularly, to providing a second regeneration path totally in a closed loop, a closed cycle desiccant regeneration system wherein an array of heat exchangers recovers a major percentage of the thermal energy that drives the cycle with only condensation constituting energy lost.
2. Description of the Prior Art
Open cycle desiccant systems have been known from the early 1940's. In 1955, Pennington U.S. Pat. No. 2,700,537 was using rotary heat exchangers impregnated with desiccants. Today dual path machines similar to FIG. 1 herein use the Pennington cycle. In 1960, Munters U.S. Pat. No. 2,926,502 improved this cycle. The '502 patent discloses an air conditioning system including the recycling of air, at least three air flow paths, with all embodiments including a recycling of interior space conditioned air path, an open cycle regeneration path and a supplementary air path for an additional heat exchanger.
U.S. Pat. No. 4,594,860 to Coellner et al discloses an open cycle desiccant air conditioning system when the regeneration path is an open cycle and very similar to Pennington's cycle. U.S. Pat. No. 2,186,844 to Smith discloses a refrigeration apparatus wherein heat from a mechanical refrigeration unit regenerates desiccant, very similar in concept to U.S. Pat. No. 5,502,975 to Brickley et al and U.S. Pat. No. 5,517,828 to Calton et al. The common factor is the open cycle regeneration path.
U.S. Pat. No. 5,353,606 to Yoho et al addresses a three path desiccant air conditioning system. Again, all these regeneration paths are open cycle.
The art of FIG. 2 herein represents a modified open cycle desiccant dryer. The open cycle regeneration path 20 intake's air to a filter 22 and across a heat exchanger 26 to pre-heat the outside air in the first section 28 and with the air heated by a heating device 30 for it to be drawn across a rotary desiccant matrix 34 pulled by a blower 38 to be recooled by a second section of a heat exchanger 40.
As will become evident, nothing in the prior art provides the benefits and advantages that the present invention offers.